I. Technical Field
The present invention relates to radomes. More specifically, the present invention relates to a novel multi-octave thick dielectric radome wall.
II. Background Art
Typical radome wall structures include the homogenous single-layer (monolithic), and multi-layer structures. The monolithic wall structures utilize a single slab of homogeous dielectric material. Within this category of monolithic wall structures is the thin wall structure which has a thickness of less than approximately one-tenth wavelength. Also within this category is the thick wall design where the wall thickness is an interger multiple of one-half wavelength in the dielectric.
With respect to the thin wall design, performance is acceptable at lower frequencies where the permissable electrical thickness provides adequate strength and rigidity. However, at higher frequencies the electrical performance of the thin wall design decreases. In addition, the thin wall design at higher frequencies may not provide adequate strength and rigidity since the wall thickness is a function of the frequency.
With respect to thick wall or resonant wall designs, performance is substantially limited to narrow band applications. In many applications, wide bandwidth requirements may not permit this design due to the inherent narrow band limitations. With a thick wall design, broad bandwidth performance is not achievable since transmittance is reduced at frequencies above and below the wall thickness of one-half wavelength.
Other types of radome wall structures include the multi-layer or sandwich designs. These structures typically consist of three or more layers of differing density dielectric materials. Multi-layer structures provide increased strength rigidity in the radome structure and even permit high transmittance over a broad frequency band. However, with the multi-layer structures uneven performance characteristics in the transmittance exist over the wide frequency band. These uneven performance characteristics may be unacceptable in certain applications.
It is therefore, an object of the present invention to provide a new and improved high strength dielectric radome wall structure of improved electrical performance over a broad bandwidth of frequencies.
It is yet a further object of the present invention to provide a radome wall structure which provides high transmittance over a multi-octave frequency band for high incidence and arbitrary wave polarization.